Let’s continue our journey of discovery of the different CO2 laser applications for the packaging industry. In the past articles, we’ve already described how laser micro-perforation can drill accurate holes on plastic film to create packages suitable to preserve fresh food. Laser micro-perforation applications, unlike traditional mechanical micro perforation applications, offer speed, flexibility, and extreme accuracy.

In order to improve the shelf life of products, it is often necessary to continuously control gas exchanges between the interior and the exterior of a plastic bag. Laser micro-perforation allows us to tightly control these gas transmissions, allowing us to easily package fresh products as well as preserve their quality.

It is no coincidence that the CO2 laser has seen a broad application in this field. The packaging industry knows very strict production rules and specifications. Packaging must not only guarantee the quality of the product, but must also meet requirements in terms of mechanical strength, packaging hygiene, and food safety. Besides that, all requirements also have to be reconciled with an aesthetic appearance. Poor packaging could reduce the perceived quality of the product, and is thus a crucial factor in influencing consumer buying behavior.

In this article we’re going to describe another application of the CO2 laser: we will talk about sealing plastic food bags.

Conventional methods to seal plastic food bags

Why is the CO2 laser an innovative process for the sealing of food bags? To get an answer to this question we have to briefly discuss the traditional methods used to seal plastic food bags.

Traditionally the sealing of plastic food bags is a welding process achieved through the application of heat and pressure. In this process, two sheets of plastic film are joined and welded together. This process is mostly mechanical, meaning that parts of the machine have to be changed every time a different packaging process is executed, in order to meet the packaging needs of diverse products. Traditional machines are heavy, due to their working parts that need to be fastened securely.

A production line of this kind is not flexible, while food manufacturers may need to apply different packaging techniques within the same production cycle. This would mean that the manufacturers have to the change machine parts or perform other maintenance operations, which results in lower productivity.

Laser hermetic sealing plastic food bags

The process of laser sealing of plastic bags is part of the hermetic welding process of thermoplastics. The most commonly used bags in the packaging industry are transparent and made of polypropylene or polyethylene.

These materials absorb the 10.6 μ wavelength of the CO2 laser very well. The laser beam reaches the surface of the material to be welded thanks to a scanning head. Subsequently, the laser heats up the surface so as to reach the melting temperature of the material, allowing it to weld the two plastic films together.

The entire process is incredibly fast: the speed achieved with this welding method to hermetically seal plastic bags allow to seal dozens of pieces per minute.

What are the advantages of hermetic laser sealing?

The advantages of using a laser sealing system to hermetically seal plastic food bags are endless:

• You can change the shape and size of the packaging material to be sealed without the need for long breaks in the production flow. It is not necessary to create custom-made parts since the laser can be applied to any type of container and to any type of machining even within the same production cycle.
• The sealing can even be carried out on very thin plastic films without risking any damage to the material. This allows extremely accurate machining operations and reduces the amount of material used, and thus reduces industrial waste.
• The CO2 laser is compact in size and light in weight since mechanical parts or other bulky mechanisms are not required. The laser system thus fits well into production facilities with confined spaces.
• Like any other laser process, the welding of plastic bags is a non-contact process. This means, among other things, that it is aseptic, and thus perfect for the packaging of food products.

Required components for a laser system setup

You may ask yourself right now which components are required for a laser system set-up. It is difficult to define in detail the diverse components or elements that will be part of the system. Each customer has its own needs in terms of power, production speed, material to be treated, etc. However, it is possible to define the following three basic elements of a similar system.

CO2 Laser source

The CO2 Laser source generates the laser beam that will work your materials. El.En. CO2 laser sources are available in different output powers, ranging from 150W to 1200W.

Laser scanning head

The laser scanning head is a device that “moves” the laser beam while keeping it perfectly focused on the point that needs to be worked. El.En.’s scanning head executes this process at very high-speed thanks to the beryllium mirrors mounted on galvanometric motors.

Control Software

The advantage of laser processing is that the entire process is controlled digitally. Through the software, you can control all relevant machining parameters and perform on-the-fly changes without interrupting the process workflow.

Abrasives, part of a family of materials characterised by their great hardness, are used for processes such as polishing or the sanding of surfaces. They are available in a wide variety of shapes and types and lend themselves to a multitude of processes.

These materials can be moulded into a large number of shapes: discs, brushes, wheels, cutters, grinding wheels. However, traditional abrasive processing methods have limitations that can be overcome with laser processing.

In this article we will look at the 6 advantages of using laser technology in the manufacturing process of abrasive products.

1. Laser is a non-contact process

The main problem in the manufacturing of abrasives is that the abrasive action is also exerted on the tool itself. Let us take flexible abrasives as an example. In this category of abrasives, the abrasive substance is sprinkled on a backing, which is normally made of paper or a polymer material. In order to obtain the desired shapes, such as a rotating disc or wheel, tools such as dies are used, i.e. a mechanical method that uses contact between parts to separate an element from the die into the desired shape.

Operations such as die cutting of abrasive materials, however, have a drawback. The abrasive action is also exerted on the cutting tools. Blades, dies and cutters quickly get worn out and must be replaced frequently to maintain high machining quality. This increases machining costs, which consequently increases the cost of the final product.

Laser cutting of abrasive materials overcomes this disadvantage. It is characterised by a total absence of contact. The laser beam interacts remotely with the surface of the material in a non-mechanical process that avoids the problem of continuous wear of the machining tools.

2. Laser is a versatile tool

A major disadvantage of traditional machining methods is also their lack of flexibility. For example, a die made to create a specific shape can only be used to create that specific shape. To make differently shaped parts, it is necessary to create new diecuts, provided that the investment required to create them is justified by a profitable return.

Similarly, only one machining operation can be performed with traditional machining tools. A die-cutting tool can only perform one machining operation. A cutting tool can only perform cutting. To perform different machining operations, one must change the machining tool. If a manufacturer wanted to apply information to an abrasive disc such as grit size or a serial number, he would have to insert the part into a dedicated machine, such as a printing machine.

Laser systems, on the other hand, allow several machining operations to be performed in a single session. With the same system, flexible discs can be cut from a die, cuts and perforations can be made and surface information on a material can be added through laser marking. In addition, the use of lasers allows the shape or size of the piece being manufactured to be changed in real time, without any additional aids. It is precisely its high flexibility that makes the laser the trump card for this type of application.

Laser offers a true change in the very way production is understood. It gives manufacturers the possibility of enormously expanding their commercial offerings. It becomes possible to create prototypes, just-in-time production, or series of small parts for high-value customers.

3. Laser is a precise tool

Abrasives are used in many different industries. Each of them requires specific processes, and, therefore, abrasive tools that are shaped differently. This means that there are more or less specialised tools: from simple sandpaper, sold in rolls and used by carpenters and craftsmen, to customised rotating discs for high-precision machining.

However, mechanical machining tools have a tolerance limit beyond which they cannot go. The size of the machining tools, their design, and the need to avoid unwanted contact limit the complexity of the machining that can be performed.

Laser, on the other hand, allows very tight tolerances. Since there is no contact between the parts, the tool can follow intricate cutting paths, create microscopic perforations and special shapes, make surface cuts and other machining operations that would be impossible with mechanical cutting tools.

4. Laser reduces machining waste

With traditional machining tools, processing is performed by the mechanical removal of material. The process tends to produce machining waste, dust and other residues that must be managed in some way, with a variable economic and environmental cost.

Laser machining processes, on the other hand, tend not to produce waste. Material removal occurs through sublimation. The very high energy density produced by the laser on the surface allows the temperature of the material to rise, instantly vaporising it as a result of a transformation of the material state.

5. Laser respects materials

Mechanical machining processes present a risk of damage to products due to accidental contact or excessive mechanical contact. Any deformation lowers the quality of the final product.

In laser processing, there is no risk of damage from mechanical contact. Laser processing respects all materials, even the most delicate ones. They guarantee a higher quality of the finished part and are therefore ideal for the sectors in which the degree of error must be kept down to a minimum.

6. Laser is an environmentally friendly process

Laser processing offers high energy efficiency. All things being equal, laser performs the processing with much lower energy expenditure than mechanical processing. This, combined with the absence of waste, makes the laser one of the most environmentally friendly processing tools available to manufacturers.

Contact us

Laser is a cost-effective tool for the manufacturing of abrasive materials. Because the possible applications are numerous, seeking the advice of an expert can help you find the most suitable processing system for your application. El.En. CO2 laser systems are ideal for the manufacturing of abrasive materials. Contact us for more information.

Plastic processing was one of the sectors in which the introduction of the CO₂ laser was immediately appreciated. Laser has made it possible to carry out faster, more precise and less wasteful processes.

Flexibility has been the watchword that made new methods possible andopened up new areas of application for plastic processing.

The word “plastic” is quite inaccurate: it covers a large number of materials which have very different behaviors, mechanical characteristics, workability and possible applications.

Cutting, drilling and marking are the main processes that can be carried out with CO₂ laser. Plastic objects are cut by gradually removing the material until the laser beam penetrates through its entire thickness.

Some plastics lend themselves more to cutting than others. The best results with laser are obtained with acrylic (PMMA) and polypropylene (PP). On these plastics, the cut comes out with smooth, shiny edges and without any scorch marks.

CO₂ laser marking for plastic is based on the same principle as laser cuts; though in this case, the beam only removes a surface layer, leaving an indelible mark.

In theory, laser can mark any type of logo, code or figure on plastic, but in reality, the possible applications depend on the material used. Some materials respond better to cutting operations, while others are more suitable for marking.

But what does this great variability of behavior between one plastic and another depend on? The difference lies in the different disposition of the monomers, the repetitive molecular units within the polymer. Variations in temperature have an effect on the material properties and behaviour.

In fact, all plastics are processed with the use of heat. Depending on how they respond to it, plastics fall into two categories: thermosets and thermoplastics.

Examples of thermosetting polymers are:

• polyimide
• polyurethane
• bakelite

The main thermoplastic polymers are:

• polyethylene
• polystyrene
• polypropylene
• polyacrylic
• polyamide
• nylon
• ABS

Thermoplastic polymers, up to a certain threshold (called glass transition temperature), behave like a crystalline solid. Beyond this temperature they first transition to a rubbery state and then finally melt. These polymers are made up of linear chains, which explains why they can be melted and easily molded at certain temperatures.

Thermosetting polymers on the other hand, stiffen as the temperature increases until they reach melting point, beyond which a change of state occurs. Cross-linking within the macromolecule, makes them less susceptible to temperature differences.

Because of these substantial differences, not all plastics respond well to laser. In general, thermoplastics lend themselves better to laser processing, but even thermosets can, to some extent, be subjected to laser processing.

In the following tables we have summarized the result of the interaction between the various polymers and the laser.

As you can see, the results vary widely. A case by case analysis is recommended to understand which application works best. Plus, more plastics can undergo laser cutting: teflon (PTFE) is on of those.

How to choose the right laser system for plastic

The introduction of laser in plastic processing has paved the way for new applications. Laser processing of plastic is very convenient. Most commonly used polymers are perfectly compatible with the CO₂ laser.

But choosing the most suitable laser system is not easy. The variables to take into consideration are many: the type of application, the type of material, and the production needs.

El. En. has produced laser systems for plastic processing for over 35 years. If you have an application in mind and aren’t sure how to make it, contact us. We will be more than happy to help you.

Wood, paper, cardboard, plastic, PMMA. And also rubber, leather, metals, and ceramics: CO2 lasers can cut a great number of materials. For this reason, CO2 lasers have become the most widely diffused laser technology for laser material processing.

However, despite the wide use of the CO2 laser we receive a lot of questions on possible appications that can all be summed up by what materials can be cut by CO2 laser? In this article we answer to this question with a simple list of materials that can be easily cut with CO2 lasers (the links take to articles that examine each topic in depth): 

• Wood based materials
• Paper based materials
• Acrylic (PMMA) and other plastic polymers
• Leather and faux leather
• Natural and synthetic fabric
• Biologic materialAll industrial sectors that need to process these materials can thus use the laser CO2 for a faster, smoother, and more precise cutting process.

Fields of application

To go into the details, the following list displays the main applications of CO2 laser cutting, ordered by industry:

• Papermaking industry
• Cutting cardboard boxes
• Cutting paper and cardboard
• Stencil cut
• Decorations

• Woodworking industry
• The cutting of any kind, and thickness, of wood, especially Plywood and MDF
• Inlay fine wood
• Engravings of any kind

• Engravings and inlays
• Laser engraving and cutting methacrylate
• Laser engraving and cutting leather goods
• Laser engraving name and number plates
• Laser engraving and cutting textiles
• Laser engraving electronic components
• Laser engraving anodized aluminum and varnished metals. N.B.: the CO2 laser usually doesn’t cut metal but can label or mark them indelibly.
• Engraving of glass, marble, and stones
• Inlays on ivory

• Creation and Customization
• Laser cutting hollow punches
• Laser cutting for architectural models
• Laser cutting plastic, cardboard, or wooden displays.
• Contour and cut labels
• Personalizing gadgets
• Personalizing buttons
• Material machining for model making

The list above is just a short list of the many different materials that can be processed by the CO2 lasers: there are lots of other materials that can be cut with the CO2 laser. Research on the applications of the CO2 laser is still an ongoing process, of which experimentation plays an important role: only experimentation provides us with certainty about the possible applications. For this reason we invite you to contact us whereby the material you want to work is not presented in the above list. Together we will find you the solution that fits your needs!

Over the years, different types of lasers have established themselves thanks to their versatility. Apart from technical differences in construction, the particularity of each laser lies in the propagation medium used to emit energy and the resulting wavelength.

The most common are gas lasers (such as the CO2 laser), semiconductor lasers, fibre optic lasers and solid-state lasers. Depending on the medium used, the laser generates a beam at a different wavelength. The lasers manufactured so far cover the entire electromagnetic spectrum.

Why the laser wavelength is key

The wavelength is crucial in determining the possible uses of a laser. From it depends the kind of interactions between the laser and the material. Each material responds differently to a certain wavelength. Some materials, like acrylic, can absorb in the near IR or be transparent in the far IR. The optimum balance is achieved when most of the energy generated by the laser is absorbed by the material, allowing efficient processing.

Based on what we have said, it is impossible to establish an optimal wavelength. The choice depends on the characteristics of the material to be processed.

However, it is possible to give general indications. It has been demonstrated that some lasers have a wavelength which makes them suitable for a wide range of applications.

The wavelength of CO2 laser

The CO2 laser in particular has a wavelength of 10.6 micrometres, which is in the far-infrared region. This length is absorbed very well by all materials containing carbon. Wood, paper, plastic polymers, organic materials, natural and synthetic fabrics respond perfectly to CO2 laser radiation.

What’s your need?

Certainly, of all lasers, the carbon dioxide laser has proved to have the greatest versatility and has therefore established itself as the main choice for the laser processing of materials. Contact us for more information!

Laser kiss cutting (or kiss die cut) consists in removing the superficial portion of a sheet of material according to a specific cutting path.

Unlike normal laser cutting, laser kiss cutting does not go through all the material but remains on the surface layer.

Due to this characteristic, kiss cutting is mainly used in the paper converting and textile industries.

Laser kiss cutting is used when the superficial layer of a material made up of two attached sheets must be cut.

Laser die cutting of labels is an example of one of the most common applications of kiss cutting. The laser cuts out the surface layer into the shape of the adhesive to facilitate its removal from the support layer.

Laser kiss cutting can also be applied to the field of fabric decoration.

Kiss cutting for digital converting

Digital converting or laser converting is used to perform paper converting processes that would be difficult or impossible to achieve with conventional mechanical methods.

Laser kiss cutting is a typical digital converting application that, as previously mentioned, is particularly used in the production of adhesive labels.

This technique makes production particularly efficient and advantageous, since the costs and time required to set up the machine are eliminated.

In this sector, the materials most used for kiss cutting are:

• paper and derivatives
• polyester
• plastic film
• adhesive tape

Kiss cutting for the textile sector

In the textile industry, laser kiss cutting and laser cutting are used to decorate both semi-finished fabrics and finished garments. In the latter case, laser kiss cutting is very useful for creating personalized decorations.

This technique makes it possible to create different effects such as embroideries, appliqués and labels of various types.

Generally speaking, in this family of applications, two pieces of fabric are sewn together.

Laser kiss cutting then cuts out a shape on the surface layer of the fabric. The upper shape is then removed making the underlying drawing visible.

Kiss cutting is applied mainly on the following textile materials:

• synthetic fabrics in general, in particular polyester and polyethylene
• natural fabrics, especially cotton

The advantages of laser kiss cutting

The kiss cutting technique is not a modern discovery related to laser technology but dates back to traditional printing techniques.

Compared to these mechanical cutting methods based on blades and dies, laser kiss cutting offers several advantages:

• the cutting path can be very complex, making detailed and precise cuts
• the possibilities for customization are innumerable even within the same production cycle
• it can be performed on a large number of materials without interrupting production
• cutting tools don’t get worn during production which therefore eliminates the need for maintenance
• speed, productivity and processing quality are at their maximum
• edges are clean cut and defined and do not need further finishing

The industries of laser kiss cutting

As we have seen, laser kiss cutting is mainly used in the digital converting and textile decoration sectors.

Examples of laser kiss cutting

Which laser systems are suitable for laser kiss cutting

Each laser kiss cutting application must be tailor made for each customer’s needs. In the label industry, a system consisting of a CO₂ laser source and a scanning head is generally used.

The laser source

For the manufacturing of labels, high power isn’t necessary: most applications can be done with a laser source below 500W.

Keep in mind though that the power is directly proportional to the production speed. It is therefore sometimes necessary to resort to higher power because of production needs.

A small clarification on the source’s wavelength: El.En. has developed a CO₂ laser source specially designed for label manufacturing, the RF333P, with a wavelength of 10.2 micrometers.

This wavelength is ideal for polypropylene (PP), of which is made the surface layer of most labels is made. This source is a variant of the Self Refilling series, which are the most suitable for paper labels.

The scanning heads

The scanning head always works in combination with a laser source. Its function is to move the laser beam on the work surface and keep it focused. To do this work the source uses mirrors mounted on galvo motors and a focusing lens on the Z axis.

El.En. produced a scanning head for CO₂ lasers called GioScan. The machine is available in two models:

• GioScan 1735, capable of operating on a surface between 135×135 mm and 800×800 mm
• GioScan 1770HR, capable of operating on a maximum area of ​​2300×2300 mm

A laser system for each laser application

Laser kiss cutting applications are numerous and ultimately depend on the material and production needs.

The advantage of laser technology is that it is possible to create custom applications.

For over 35 years El.En. has produced laser systems for industrial applications.

If you have a production idea in mind that requires laser kiss cutting,

Laser micro-perforation of plastic bags for fresh products

The CO2 laser has been on the market for many decades. Over the years it has proven to be a sturdy tool, capable of providing thousands of hours of processing without having to be serviced or replaced.

Unlike for mechanical production equipment, one of the biggest advantages of laser processing is low maintenance.

Mechanical tools operate by contact between parts and rely on moving mechanisms. The friction generated during machine operation makes wear and tear on this production equipment a pressing problem. Periodically, production has to be stopped in order to carry out the necessary maintenance operations, which increases the costs of operation and processing. The die sector is but one example of an industrial process that suffers from this problem. In this type of application, the dies have to be replaced periodically to guarantee the quality of the cut.

Laser, on the other hand, is a non-contact process. The entire laser system is based on the production and transmission of electronic pulses and the generation of polarised light beams. There are no moving parts or friction and therefore no direct impact on the lifetime of the laser source.

However, this does not mean that laser sources are maintenance-free. Laser sources also wear out, albeit much more slowly. This is why they need regular maintenance.

In the case of CO2 laser sources, the main problem is the rarefaction of the gas inside the laser tube. Year after year, the gas mixture is normally depleted, resulting in around a 1-2% emitted power decrease per year. This causes a gradual deterioration of the processing and a consequent decrease in efficiency.

The only solution to this problem is to periodically regenerate the laser source. However, this is a costly and time-consuming operation that usually involves stopping the production line, resulting in a negative impact on productivity.

El.En. has created a series of laser sources based on Self-Refilling technology to overcome this very problem. These sources, called Never Ending Power, avoid the regeneration of the source thanks to the use of a cylinder that contains the propagation medium. This cylinder can easily be replaced without causing any delays and guarantees the same process parameters and power over time.

This innovative recharging technology now makes it possible to have a laser source that always functions at maximum power. The laser beam’s quality will consistently remain at its highest level and the lifespan of the laser source will practically be infinite. Contact us for more information!

The laser scanning heads are a fundamental component of the galvo systems for laser cutting and marking. These devices deflect the laser beam coming from the source and move it along the X and Y axes according to the operation required.

The components of a galvo head for laser

A scanning head is made of different components.

Galvo mirrors

Mirrors mounted on galvanometric rotary motors deflect the laser beam. These motors transform electrical voltage into angular movement.

The mirrors, mounted perpendicularly on the engines, move the laser beam along the X and Y axes according to the input received from the motor.

The big advantage of these devices is that they can reach a very high acceleration and speed of movement.

The size of the mirror depends on the laser beam. As the diameter and the power of the beam increase so must the diameter of the mirror. The same size in turn influences the acceleration and speed of the engine’s angular movement. The smaller mirrors reach higher accelerations than the larger mirrors.

In the range of El.En.’s products there are galvanometric mirrors for different applications. Find out more about our complete 2-axis CO₂ laser galvanometer mirror line on our website.

Z-linear optics

Galvo mirrors are not the only components of a scanning head. The z-linear lens, which focuses the laser on the work surface, has an important role to play too.

To focus the laser beam and get it to work optimally, the focal length of the lens must vary based on the distance between the scanning head and the point it needs to reach on the surface.

The z-linear lens changes the focal length in real time and maintains the laser beam in focus regardless of its distance from the workpiece.

The control software

The control software makes sure that all the moving parts of the scanning head stay coordinated.

It transforms a vector file (the place where the work to be performed is described), into a path for the laser beam. The control software makes the galvo head and the laser source work together to achieve the desired result.

What processing can be performed with a laser galvo head?

As previously mentioned, the laser galvo heads are mainly used for cutting and laser marking.

Laser galvo cutting

Galvo heads make it possible to reach high processing speeds for cutting applications. Galvo heads are perfect for the processing of thin materials such as paper, cardboard and plastic film.

The head can cut out any shape quickly.

Some of the industries that benefit most from the use of galvanometric motors are the adhesive label sector that use kiss-cutting applications and the packaging industry that uses galvo-laser applications to make products with advanced features.

Galvo laser marking

The main marking applications include the marking of various types of alphanumeric codes, such as barcodes and QR codes, and the engraving of ornamental motifs for decoration.

Laser marking can be performed on different materials such as thermoplastic polymers, wood, fabrics, leather, metals, glass.

In the case of transparent materials it is also possible to perform the impression of three-dimensional figures inside the object.

The advantages of laser galvo heads

Laser applications get many advantages from the use of galvo heads:

• Speed ​​- The galvanometric motors reach very high angular speeds. This means that the laser beam moves over the surface of the workpiece with speeds reaching tens of centimeters per second. Thanks to this the productivity of a laser galvo system is very high.
• Integration – Precisely because of this characteristic, galvo laser systems are suitable for integration into larger production flows. A laser galvo system consisting of a scanning head and a laser source performs best when inserted into automated processes. Furthermore, it is compact enough to be easily added to pre-existing systems, giving it an important upgrade without major changes.
• Quality – The laser galvo systems guarantee high quality and detailed results. In marking applications, the scanning head gives the possibility to create a wide range of effects, including the reproduction of a photograph on a surface.

One device, many tools

Scanning heads are a key tool in laser material processing applications. They transform a single beam of polarized light into an instrument with many applications.

To choose the scanning head that is most compatible with the application you need, request the help of an expert. Get in touch with us: our team at El.En. will be happy to help you find the most suitable laser scanning head for your applications.

Laser labeling of food is a recent innovation that makes it possible to reduce production waste by replacing traditional food labels with laser engraved labels. Laser marking of food is suitable for companies wanting to optimize their production process, saving resources and materials while also decreasing their ecological footprint. The possibilities are endless.

In fact, an increasing number of companies have realized that laser techniques are the key to process innovation. In a recent article we discussed the growing phenomena of natural branding, a process in which traditional food labels are replaced by the laser marking of the skin of food.

Fresh products such as fruits and vegetables can easily be marked through a laser scanning head, a low power CO2 laser source and a software that controls the process. This procedure of laser marking permits us to imprint logos, barcodes, and any type of information on different types of food without affecting their quality. The marking does not affect the organoleptic properties of the food – it is a “friendly process” as it only affects the most superficial layer of the skin of fresh products.

However, fruits and vegetables are not the only types of food that can be marked with the CO2 laser technology. Results have shown that even seasoned and semi-seasoned cheese and hams can be marked.

A case study: machine designed to mark seasoned and semi-seasoned cheese.

These seasoned and semi-seasoned products have always been marked through heat methods. Products are marked with their brand and codes that establishes the batch of production, identify the producer, allow to trace back the origin of the product. The easiest system to mark food is to use a metal to impress a brand by burning the surface of the product.

This traditional method, while being inexpensive, is incredibly slow and inflexible. In order to change the codes to be imprinted, a change in the marking tool is needed.

A more efficient way of imprinting information on food is to use the CO2 laser application. The laser allows to mark the surface of these products faster, with higher precision, and in a more secure way. In comparison to traditional ways of marking food, such as marking through means of heat, laser marking allows us to have an extremely precise process: it provides the possibility to adapt all parameters involved to suit the characteristics of the product to be marked. In this way the process of laser marking becomes the more precise way as it respects the unique characteristics of each product.

A system for marking the dairy products may consist of the following elements:

• Completely washable stainless steel structure
• Conveyer belt
• CO2 laser source
• High performance laser scanning head
• Controlling software

The functioning is semi-automated. The system involves the presence of an operator placing the products to be marked on the conveyer belt. The conveyer belt transports the products to the laser processing space, isolated from the outside with doors that can be opened for inspection and sanitation reasons. Here the laser scanning head, controlled by a software, guides the laser beam on the surface of the product, performing the marking within seconds. In a few minutes only, the operator is able to perform the same operation dozens of times.

The advantage of such a system is its flexibility. First of all, the machine is designed to be modular: each module can be replicated and adapted to the needs of the manufacturer. For example, you can install different laser sources for different applications.

Furthermore, the system allows you to change the information you want to mark very quickly. You just have to modify the parameters inserted in the control software to perform a different process.